Air compressor



2 Sheets -Sheet 1.

' INVENTOR ATTORNEY AIR COMPRESSOR.

Patented Deo. 25, 1883..

N PETERS rmwmm n l n Wauhington, a c.

T. P. FREEMAN.

(No Model.)

WITNESSES (No Model.) 2 Sheets-Sheet 2.

T. P. FREEMAN.

AIR COMPRESSOR.

"No. 290,764. Patented Dec. 25, 1883-.

fi-frfi-g'frfi' i i 1' i i I i i i i I l i i i i I 1 I i I i --'.Qr-4J WITNESSES: INVENTOR Q r -37omut% ATTORNEY N PETERS. Pmmuum mr. Washington. D. c.

-UNlTED STATES Price.

PATENT THOMAS F. FREEMAN, on BROOKLYN, ASSIGNOR TO WILL-1AM KOCH, on NEW YORK, N. Y.

AIR-COMPRESSOR.

SBECIFICATION'forming part of Letters Patent No. 290,764, dated December 25, 1883.

Application filed March 30, 1883.

To all whom it may concern Be it known that I, THOMAS F. FREEMAN, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Compressors, of which the following is a specification.

The said improvements relate to machines that are used for compressing air or gas for refrigerating. purposes. A pair of single-acting plunger-pumps provided with suitable valves are driven by a connecting-rod from a crank-shaft operated by a small engine, or in any other convenient manner. In a machine employed upon ammoniacal gas which is returned to the machine, (and it is important there should be no connection between the interior of the machine and the external air,)

the lubricating material is collected in closed receptacles and returned by suitable pipes.

In the drawings hereto annexed, Figure l is an elevation, in longitudinal section, of a machine made according to my improvements. Fig. 2 is a transverse section of the same, and Fig. 3 is a section of the valve which I prefer to use in the connecting-pipes of the machine. Fig. 4 is an enlarged representation of a collar in the stuffing-box of the machine, showing it in end and side elevations.

The revolving shaft a is driven by the beltpulley b, and the crank 0 within the machine operates the plungers d d by the connectingrod e. The two plungers are made in one casting, or are secured together so that one connection drives both pumps. The pump-barrels are lined or made of two thicknesses, as shown in the drawings, that there may be no continuity of blow-holes or pores in the metal to occasion leakage. The suction-valves f f in the bottoms of the plungers, and the delivery-valves g g at the ends of the pump-barrels, are placed at a slight incline, to facilitate their seating by gravity, as well as by the clasticity of the gas. It is essential that the valves .45 f be made conical, that they may be readily ground and kept tight in their seats in the moving piston. In the delivery-pipes h h of each pump there is an additional check-valve, i, to prevent the return or downward flow of (No model.)

to keep the other part in operation, the delivcry-pipes are furnished with stop-cocks Z Z, which are shown in section in Fig. 3. The inlet is at the bottom of the plug, which is made with a shoulder at the top, so that the packing and the gland at m keep the plug in position. Under the gland and inside the stufling-box there is an additional loose ring that compresses the packing below the gland. These cocks are shown in the drawings with only a single passage; but they may be made in the same manner as a three or four way cook.

The lubricating material, which is supplied by the pipes at n, is carried through the valves of the machine and settles in the oil-receptacles WVhen the compressed air or gas has 0 o, whence it may be pumped by the pump 1) and returned to the oil-cups. The pump may be worked by hand,when required, or operated continuously by any appropriate connection with the working machinery. Then the machine is in operation, the pressure of the compressed gas will drive the oil from the receptacle 0 into the pump-barrel when the plunger is being withdrawn, and the pipes at are supplied with cocks to enable this to be effected. The oil-pipes are also connected with a grooved sleeve, q, within the shaft stuffing-box, (shown in Fig. 2,) so that the grooved metallic ring placed between the parts of the packing may be kept supplied with oil to form an oil seal. This sleeve is shown separately on an enlarged scale in Fig. 4. The oil reaches the grooves on the internal surface, where the seal is needed on account of the motion and wear of the shaft, by'means of the leakage around the parts that are not purposely fitted with an oiltight joint.

Both the pump-barrels and their connections IO pose stated.

2. In a gas-compressing machine, the comblnation of the oil-pipe n, the Well 0, and the independent pump 1), by which the oil may be returned under a pressure in excess of that in the compressor, substantially as described.

3. In the stuffing-box of a compressing-machine, the sleeve q, with grooves on its interior i surface for the reception of oil, in the manner described.

THOMAS F. FREEMAN.

Witnesses:

VVILLIAM KOCH, 7M. KEMBLE HALL. 

